[Federal Register Volume 63, Number 129 (Tuesday, July 7, 1998)]
[Proposed Rules]
[Pages 36619-36621]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-17915]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 63, No. 129 / Tuesday, July 7, 1998 / 
Proposed Rules

[[Page 36619]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-179-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-8-100, -200, and 
-300 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all de Havilland Model DHC-8-100, 
-200, and -300 series airplanes. This proposal would require 
installation of a placard on the instrument panel of the cockpit to 
advise the flightcrew that positioning of the power levers below the 
flight idle stop during flight is prohibited. This proposal also would 
require eventual installation of a system that would prevent such 
positioning of the power levers during flight. Such installation would 
terminate the requirement for installation of a placard. This proposal 
is prompted by reports of operation of the airplane with the power 
levers positioned below the flight idle stop during flight. The actions 
specified by the proposed AD are intended to prevent such positioning 
of the power levers below the flight idle stop during flight, which 
could cause engine overspeed, possible engine damage or failure, and 
consequent reduced controllability of the airplane.

DATES: Comments must be received by October 5, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-179-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    Information concerning this proposed rule may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Engine and Propeller Directorate, New York 
Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley 
Stream, New York.

FOR FURTHER INFORMATION CONTACT: James E. Delisio, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7521; 
fax (516) 568-2716.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-179-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 98-NM-179-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of operation of the airplane with the 
power levers positioned below the flight idle stop during flight on de 
Havilland Model DHC-8-100, -200, and -300 series airplanes. One report 
indicated that such operation resulted in significant engine damage.
    When the power levers are positioned below the flight idle stop 
during flight, the propellers operate in the beta range. Under these 
conditions, it is possible for air loads to back-drive the propeller, 
which could result in overspeed of the propeller and power turbine of 
the engine. (``Beta,'' as defined in this proposed rule, is the range 
of propeller operation intended for use during taxi, ground idle, or 
reverse operations, as controlled by the power lever settings aft of 
the flight idle stop.)
    Operation of the propellers in the beta range during flight due to 
positioning of the power levers below the flight idle stop, could 
result in engine overspeed, possible engine damage or failure, and 
consequent reduced controllability of the airplane.

U.S. Type Certification of the Airplane

    This airplane model is manufactured in Canada and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations and the applicable 
bilateral airworthiness agreement. The FAA has reviewed all available 
information and determined that AD action is necessary for products of 
these type designs that are certificated for operation in the United 
States.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require installation of a 
placard on the instrument panel of the cockpit to advise the flightcrew 
that positioning of the power levers below the flight idle stop during 
flight is prohibited. Additionally, the proposed AD would require 
eventual installation of an FAA-approved system that would prevent

[[Page 36620]]

such positioning of the power levers during flight. Installation of 
that system would eliminate the requirement for installation of the 
placard. Installation of such an FAA-approved system would be required 
to be accomplished in accordance with a method approved by the FAA.
    Additionally, the FAA has included a provision [paragraph (c) of 
the proposal] for Master Minimum Equipment List (MMEL) relief in the 
event the system proposed in paragraph (b) of the proposal malfunctions 
or the use of an override (if installed) has been necessary. If 
provision is not made for MMEL relief, the system required by paragraph 
(b) would be required all of the time. Absence of such MMEL relief 
could create a burden for operators if required maintenance or repair 
was not readily available at certain airports or locations. The 
proposed MMEL relief is based on the condition that the existing manual 
power lever flight idle gate and lifting finger trigger latch design is 
retained and remains fully functional. This is consistent with the 
current MMEL that makes no mention of the flight idle gate and lifting 
finger trigger latch design, which means these devices must be 
operational at all times.

Cost Impact

    The FAA estimates that 185 de Havilland Model DHC-8-100, and -200, 
and -300 series airplanes of U.S. registry would be affected by this 
proposed AD, that it would take approximately 1 work hour per airplane 
to accomplish the installation of the placard, and that the average 
labor rate is $60 per work hour. Based on these figures, the cost 
impact of the proposed placard installation on U.S. operators is 
estimated to be $11,100, or $60 per airplane.
    Since the manufacturer has not yet developed a specific system 
commensurate with the requirements of this proposal, the FAA is unable 
to provide specific information as to the number of work hours or cost 
of parts that would be required to accomplish the proposed 
installation. However, based on similar installations of such systems 
accomplished previously on other airplane models, the FAA can 
reasonably estimate that approximately 130 work hours per airplane may 
be necessary to accomplish the system installation. The FAA also 
estimates that required parts would cost approximately $10,000 per 
airplane. Based on these figures, the cost impact of the proposed 
system installation on U.S. operators is estimated to be $3,293,000, or 
$17,800 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.
    The FAA recognizes that the obligation to maintain aircraft in an 
airworthy condition is vital, but sometimes expensive. Because AD's 
require specific actions to address specific unsafe conditions, they 
appear to impose costs that would not otherwise be borne by operators. 
However, because of the general obligation of operators to maintain 
aircraft in an airworthy condition, this appearance is deceptive. 
Attributing those costs solely to the issuance of this AD is 
unrealistic because, in the interest of maintaining safe aircraft, 
prudent operators would accomplish the required actions even if they 
were not required to do so by the AD.
    A full cost-benefit analysis has not been accomplished for this 
proposed AD. As a matter of law, in order to be airworthy, an aircraft 
must conform to its type design and be in a condition for safe 
operation. The type design is approved only after the FAA makes a 
determination that it complies with all applicable airworthiness 
requirements. In adopting and maintaining those requirements, the FAA 
already has made the determination that they establish a level of 
safety that is cost-beneficial. When the FAA, as in this proposed AD, 
makes a finding of an unsafe condition, this means that the original 
cost-benefit level of safety is no longer being achieved and that the 
proposed actions are necessary to restore that level of safety. Because 
this level of safety has already been determined to be cost-beneficial, 
a full cost-benefit analysis for this proposed AD would be redundant 
and unnecessary.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:
De Havilland: Docket 98-NM-179-AD.
    Applicability: All Model DHC-8-100, -200, and -300 airplanes, 
certificated in any category.
    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent positioning of the power levers below the flight idle 
stop during flight, which could cause engine overspeed, possible 
engine damage or failure, and consequent reduced controllability of 
the airplane, accomplish the following:
    (a) Within 30 days after the effective date of this AD, install 
a placard in a prominent location on the instrument panel of the 
cockpit that states:

Positioning of the power levers below the flight idle stop during 
flight is prohibited.

[[Page 36621]]

Such positioning may lead to loss of airplane control, or may result 
in an engine overspeed condition and consequent loss of engine 
power.
    (b) Within 1 year after the effective date of this AD, install a 
system that would prevent positioning the power levers below the 
flight idle stop during flight, in accordance with a method approved 
by the Manager, New York Aircraft Certification Office (ACO), FAA, 
Engine and Propeller Directorate. Following accomplishment of that 
installation, the placard required by paragraph (a) of this AD may 
be removed.
    (c) In the event that the system required by paragraph (b) of 
this AD malfunctions, or if the use of an override (if installed) 
has been necessary, the airplane may be operated for two days to a 
location where required maintenance/repair can be performed, 
provided the system required by paragraph (b) of this AD has been 
properly deactivated and placarded for flightcrew awareness, in 
accordance with the FAA-approved Master Minimum Equipment List 
(MMEL).
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, New York ACO. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, New York ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.
    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on June 29, 1998.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-17915 Filed 7-6-98; 8:45 am]
BILLING CODE 4910-13-U